Washing of filaments



Patented May 2, 1933 UNITED STATES P ATE JULIUS O. FUNCKE, OF ELIZABETHTON, AND RICHARD ELSSNER, OF JOHNSON CITY,

TENNESSEE, ASSIGNORS TO AIYIERICAN GLANZSTOFF CORPORATION, OF NEW YORK,

N. Y., A CORPORATION OF DELAWARE WASHING or FILAMENTS No Drawing.

Our present invention relates to an improved method of washing viscose yarn wound upon perforated or corrugated spools, or bobbins.

One object of our invention is to prevent the precipitation of salts, oxides or sulphides which will cause the presence of colored spots on the yarn, especially on the inside.

In the production of artificial yarn by the viscose process, the freshly spun filaments are usually wound directly on perforated or corrugated spools, or bobbins. The filled spools or bobbins are then placed in a washing device where the Wash water, usually at a temperature of from 2035 C. is sucked or forced through the spools by means of vacuum or pressure imparted to the interior or exterior of the spools. The amount of vacuum or pressure used varies but generally a vacuum of from 12 to 18 inches or its equivalent pressure, may be used. By means of such washing the precipitating bath liquid is removed from the yarn.

It has been found, however, that such treatment, causes the carbon disulphide to be liberated suddenly and irregularly on the inside of the spool causing a. foaming action to take place. It is our idea that by this foaming the soluted or dispersed salts or oxides of the adhering precipitating bath liquids are precipitated, together with amorphous sulphur, especially if the foaming takes place after a greater part of the acid has been removed and the Wash water is nearly neutral. The yarn is then subjected to a desulphurizing bath which changes the precipitated salts or acids to sulphides which appear on the inner layer of the yarn as spots, generally black in color.

lVe have found that these spots can be eliminated if instead of using wash water at 2035 (1., water at from 4075 C. is used. The use of water at such temperature prevents the foaming above referred to, and re- Serial No. 560,230.

sults in a yarn practically objectionable dirty spots.

The following is given to illustrate the application of our new washing process, it being understood that it is given only by way of illustration and that other temperatures and pressures may be employed without departing from the scope of our invention.

EwampZe:About 70 grams viscose yarn, 150 denier with 32 filaments, soft luster, is spun on a perforated spool with a circumference of 230 mm and a length of 130 mm. Nearly 500 of these spools are put into a rubber lined tank, the tank is filled with about 1700 liters of Water with a temperature of about 50 C. This water is sucked through the spools by a vacuum from about 14l20 inches during 50100 minutes, after that time free from any the water is drained, and the tank is refilled with an ammonium-sulphide solution of about C. This solution is sucked through the spools at the same vacuum as used for the water wash, during 50100 minutes. Then the ammonium-sulphide is drained, and the spools are washed in water again, and if necessary, they are bleached.

Having now described our invention as required by the patent statutes, What we desire to claim is:

1. In the manufacture of artificial filaments by the viscose process, the steps of spooling the spun filaments, passing heated water at a temperature of from 40 to 7 5 C. therethrough under the influence of a vacuum, then heated ammonium sulphide, then water,in order that colored spots in the treated yarn might be eliminated.

2. In a process for after-treating viscose yarn, the steps of washing the filaments with Water heated to about C. and then With an ammonium sulphide solution heated to about 30 C.

3. In a process for preventing the formation of colored spots on viscose yarn, due to the too rapid liberation of carbon disulphide in the after-treatment, the step of washing viscose yarn in water heated to about 50 C. and then treating with ammonium sulphide.

4:. In a process for preventing the formation of colored spots on viscose yarn, due to the too rapid liberation of carbon disulphide in the after-treatment, the step of washing the yarn in water heated to from to 75 C. and then treating with a heated desulphurizin agent.

11 testimony whereof we afiix our signatures.

JULIUS G. FUNGKE. RICHARD ELSSNER. 

